well it really depends on the grow setup. if you have a smaller confined space. for example i have 4 42 watters in my veg box and they put out 2800 lumens each. thats 11500 lumens. i have tried to use more lower wattage lamps. i can fit about 5 23 watt bulbs in ther and thats only 8750 lumens at 1750 lumens per bulb. also with the 42 watt bulbs my veg chamber stays withing the temp range of 75-80. i agree that more bulbs is better but i also thing more higher wattage bulbs. for example if you have 8 23 watts for flower, why not just have 8 42 watt instead, might cost more, produce more heat, but other than that your getting more light if you can control the heat.